Generally speaking, sputtering is a process carried out in a vacuum chamber that is filled with selected gasses. The sputtering process causes a substrate to be coated with a material from a target located within the sputtering equipment. Electrons in the chamber strike and ionize an inert gas, forming positive ions. The positive ions are then attracted to the negative target. When the ions strike the target, the ions transfer energy to the target material, causing material from the target surface to eject. Some of the ejected material adheres to and coats the surface of the substrate, commonly positioned opposite the target.
Depending on the plasma concentration, target redeposition, and other factors including sputtering, the target can develop disturbances, e.g. flakes, particles, defects, etc., that can lead to premature target replacement. Target replacement is among the reasons for unscheduled downtime faced by sputter departments.